IP Law Daily, PATENT—D. Del.: Curium, Lantheus defeat Novartis unit’s Lutathera patent suits on on-sale-bar grounds, (Jun 23, 2026)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

Pre-critical-date sales of Lutathera in Europe constituted commercial sales that triggered the on-sale bar.

The federal district court in Wilmington, Delaware, has found four patents asserted by Advanced Accelerator Applications (ADACAP), a Novartis subsidiary, against Curium and Lantheus invalid under the on-sale bar because the claimed inventions had been commercially sold more than one year before the patents’ effective filing dates. The court concluded that extensive pre-critical-date sales of Lutathera across Europe and the United Kingdom constituted commercial exploitation of the inventions and that the inventions were ready for patenting before the critical date. Further, the court found that Curium’s accused product did not infringe any asserted claim, while Lantheus’s proposed generic product infringed certain claims that were nevertheless invalid (Advanced Accelerator Applications USA, Inc. v. Lantheus Medical Imaging, Inc., No. 1:24-cv-00095-MN (D. Del. Jun. 17, 2026)).

Background. Plaintiffs Advanced Accelerator Applications USA, Inc., and Advanced Accelerator Applications SA develop and commercialize radiopharmaceutical products used in cancer treatment. ADACAP developed Lutathera, a radiopharmaceutical therapy containing Lutetium Lu 177 dotatate, approved for treating somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors. Defendants, Lantheus Medical Imaging, Inc., and Lantheus Holdings, Inc., operate in the radiopharmaceutical and diagnostic imaging industries. Defendants Curium US LLC, Curium US Holdings LLC, Curium Netherlands BV, and Curium International Trading BV develop and market nuclear medicine products and radiopharmaceutical therapies.

The asserted U.S. Patent Nos. 10,596,276 (the ’276 patent), 12,151,003 (the ’003 patent), 12,161,732 (the ’732 patent), and 12,168,063 (the ’063 patent) are titled “Stable, Concentrated Radionuclide Complex Solutions.” The patents share a common specification and generally claim manufacturing processes and formulations for radiopharmaceutical products containing Lutetium Lu 177 dotatate. According to the patents, the claimed inventions improve stability and reduce radiolytic degradation, thereby extending product shelf life and enabling centralized manufacture and shipment of ready-to-use doses to distant hospitals. Before such developments, hospitals generally prepared Lutetium Lu 177 dotatate products on site shortly before administration because radioactive decay limited storage and transportation.

Lantheus filed ANDA No. 217060 seeking approval to market a generic version of Lutathera, while Curium submitted a Section 505(b)(2) application seeking approval for its own Lutetium Lu 177 dotatate product. ADACAP subsequently filed separate Hatch-Waxman actions alleging infringement of claim 12 of the ’276 patent and claims 3 and 8 of the ’003 patent against Lantheus and claim 13 of the ’276 patent, claims 3 and 8 of the ’003 patent, claim 6 of the ’063 patent, and claims 3, 6, and 15 of the ’732 patent against Curium. The cases were consolidated for trial. Curium disputed infringement of all asserted claims, Lantheus disputed infringement of claim 12 of the ’276 patent, and both defendants challenged validity on multiple grounds, including the statutory on-sale bar. The principal issue at trial was whether Lutathera had been commercially sold more than one year before July 25, 2018, the earliest filing date in the asserted patent family, thereby triggering the on-sale bar under 35 U.S.C. § 102(a).

Commercial sales before critical date. The court first examined whether Lutathera had been the subject of commercial sales before the critical date. The evidence showed that ADACAP supplied Lutathera to hospitals and distributors throughout Europe from at least 2012 onward. Thousands of doses were sold in multiple countries, including the United Kingdom. Prices ranged from several hundred euros to €16,000 per dose, depending on the jurisdiction and reimbursement arrangements. By July 2017, ADACAP had generated more than £10 million in UK revenue from Lutathera sales.

The court found particularly significant that ADACAP repeatedly described the transactions as “sales” in SEC filings and corporate presentations. Internal business documents characterized Lutathera as “by far the most profitable” company product and highlighted the substantial margins generated by the program. Economic evidence showed that the company achieved gross margins approaching 70 percent on many transactions. These facts persuaded the court that ADACAP had engaged in commercial exploitation of the invention rather than merely providing limited access for scientific evaluation.

Experimental-use defense. ADACAP argued that the sales occurred through compassionate-use and expanded-access programs and, therefore, should not trigger the on-sale bar. The court rejected that position. Relying on Allen Engineering Corp. v. Bartell Industries, Inc., 299 F.3d 1336 (Fed. Cir. 2002), the court explained that the central question is whether experimentation, rather than commercial exploitation, was the primary purpose of the transactions. The court also cited Electromotive Division of General Motors Corp. v. Transportation Systems Division of General Electric Co., 417 F.3d 1203 (Fed. Cir. 2005), which emphasized that courts must examine the totality of circumstances surrounding alleged experimental use.

The record contained little evidence that ADACAP was systematically conducting manufacturing experiments through the sales programs. The court found no meaningful experimental protocols, testing plans, reports, or documented studies directed to the claimed manufacturing processes. Although information was collected from patients and physicians, the court concluded that it primarily concerned clinical treatment and regulatory matters rather than experimentation on the claimed inventions themselves. The court further observed that ADACAP continued collecting similar information after obtaining regulatory approval, undermining the argument that pre-approval sales were primarily experimental.

International regulatory programs. ADACAP also contended that European expanded-access programs differed fundamentally from ordinary commercial transactions and therefore should not trigger the U.S. on-sale bar. The court disagreed.

Although the programs operated within regulatory frameworks that permitted access to unapproved medicines, the court found that patients and healthcare providers paid substantial sums for Lutathera, and that ADACAP received significant revenues and profits. The existence of a regulatory pathway did not convert otherwise commercial transactions into experimental activity. The court therefore declined to exempt the sales from the reach of §102 merely because they occurred through European regulatory mechanisms.

Invention ready for patenting. The court next considered whether the invention was “ready for patenting,” the second requirement established by the Supreme Court in Pfaff v. Wells Electronics, Inc., 525 U.S. 55 (1998). The court concluded that this requirement was easily satisfied. By the critical date, ADACAP had already manufactured commercial-scale batches of Lutathera and shipped them to numerous treatment centers. More importantly, the company had submitted a comprehensive New Drug Application that described the manufacturing process in substantial detail. Expert testimony established that the NDA contained sufficient information to enable a person of ordinary skill in the art to make and use the claimed inventions. The court therefore determined that the inventions were not merely conceptual but had been fully developed and reduced to practice well before July 25, 2017.

Infringement. Before reaching the issue of invalidity, the court also addressed infringement. It found that Lantheus’s proposed product infringed claims 3 and 8 of the ’003 patent but did not infringe claim 12 of the ’276 patent. Curium prevailed entirely on the ground of infringement, with the court concluding that its product did not infringe any asserted claim. Because all asserted claims were ultimately held invalid under the on-sale bar, however, those infringement findings did not result in liability.

Finally, the court concluded that Lutathera had been commercially sold and was ready for patenting more than one year before the relevant filing date. It therefore found all asserted claims invalid under the on-sale bar.

The Case is No. 1:24-cv-00095-MN.

Judge: Noreika, M.

Attorneys: Daniel M. Silver (McCarter & English, LLP) for Advanced Accelerator Applications USA, Inc. Anne Shea Gaza (Stargatt & Taylor LLP) for Lantheus Medical Imaging, Inc.

Companies: Advanced Accelerator Applications USA, Inc.; Lantheus Medical Imaging, Inc.

Cases: Patent DelawareNews